Piston



July 28, 1925. 1,548,005

` J. E. D, ISAKSON PISTON Filed Feb, e, 1923 Immun ,9

A TTORIVE YS To all whom may concern:

raameaialy 28.1925.

UNITED STATES'l JOHN E. D. I SAKSON, 0F BROOKLYN, NEW YORK..

PISTON.

Appucatinmea february e, 192s. serial no. 617,379.

Be it known that I,'Jo11N E. D. IsAxsoN, a citizen` of the United States of America, and a reside-nt of the city of' NewYork, borough of Brooklyn, in the county of Kings and State of New York, have invvented a new and Improved Piston, of whichl the following is adescription.

My invention relates to a piston and while adapted for use generally where pistons are emplo ed, is more particularly intended for embo iment in an .engine piston.

The general object of my inventionA is to provide a iston embodying an assemblage making orY the prevention of cutting of the cylinder by the piston as well as to provide a construction by which leakage past lthe piston is minimized and whereby the piston and cylinder in vwhich it operates may be used for a long period without repairs.

The nature of the invention and its distinguishing features and characteristics will clearly appearas the description proceeds.

Reference is to be had to the accompany.

ing drawings forming a part of this specification, it being understood that the 'drawings -are merely illustrated o f one example of the invention.

Figure 1 is an end view of a piston embodying my invention;

Figure 2 is a longitudinal section through the piston as indicated by the line 2-2, Figure l; l .f

Figure `3 is a transverse section as indicated by the line 33, Figure' 2;

Figure 4 is a perspective view of one ofv the piston ring elements;

Figure 5` is a cross section through a piston ring of modified form.

In carryingout myv invention in accordance with the illustrated example the piston body or head 10 is secured as usual to the piston rod 11 by a nut 111 or equivalent means. The piston head 10 is formed with an annular flange 12 at the back and forward of the front flange 12 said piston head is formed of zones of varyin diameter, there being 'a small zone 13 a ]acent the front face of the head 10, and intermediate tapered zone 14,.larger than the zone 13, and al third still larger zone-15 adjacent to the flange 12. The piston follower -16 has a tapered fit on'the zone 13 and it maybe secured in position by studs or bolts, there being shown in the present example studs 17 having intermediate the ends thereof a fixed collar 18 countersunk in the head 10 to lie flush with that face contacting with the follower 16 and tobe overlapped b the l latter. The nuts 19 of the studs 1 countersunk in the/follower 16.

On the piston head 10 at the intermediate taperedi zone 14 is fitted a ring 20, the fit of said ring being sufficiently tlght for the ring (20) to be one with the head 10 in the movements of the latter. In the co-terminus plane of the zones 14, 15 of the piston head 10 a shoulder 110- is formed against which the ring 20 bears atthe rear surface of said ring when fitted to the tapered zone 14, the' opposite or front face of the ringl 2O lying in the same plane asthat front surface of the piston head- 10 'between the zones 13 are 'and 14. 4 The followerv"16 overlaps the front immovably held when ,said follower is secured by the studs 17 or equivalent means. At the periphery the ring`20 is formed with annular grooves 21 to hold a limited quantity of waterv of condensation. In flange 12 of head 10, at the periphery is an annular water groove 121 and a similar peripheral groove 221 is formed in follower 16.

With the ring 20 and the follower 16 inl place said ring and follower and the piston head 10 will be in fixed relation to one another.v The follower 16 at'the .inner face has a peripheral annular recessv 116, said recessat the rear'side being walled bythe -front face of the ring 20. The space or recess 116 between the follower 16 and the' i similarly in the space between the rear face of the ring 20 and the front face of peripheral flange 12 of piston head 10 is a space 112. Between the ring 20 and flange 12 in space.112, a second pair of vfloating piston rlngs 22 (or a single rihg 122) is emplaced. In the front face of the flange 12 and in the rear vface of the ring 20 are annular grooves designated respectively 23 and 24. On the rings 22 are annular tongues or beads 25 entering said grooves 23, 24. 'The grooves 23, 24 have a` greater width, that is to say, a greater dimension radial of the pistonfhan the tongues or beads 25, whereby said tongues or beads may have radial .play in the expansion of the rings 22 but the engagement of the tongues 25 in the grooves l the. rings should the said yrings become broken. In vthe front face of the fixed ring 20 and in the rear face of the follower 16 are respectively annular grooves 124 and 123, corresponding with the grooves 24.- and 23 and in said annular grooves 123, 124 are received theV annular tongueor beads 25 on the rearward pair of piston rings 22. lt will be understood that one pair of piston rings 22 may be omitted but advantageously both front and rear rings are employed in practice. l

In Figure 5 is shown a single piston ring 122 corresponding with a pair of piston rings 22, said ring 122 having the annular beads 125 at the front, and rear faces corresponding with the tongues or'beads 25. ln the rings 22 are formed peripheral annular steam grooves 27, communicating with which are radial steam passages 28. The fit of the rings 22 or the ring 122 is such as to permit steam to pass to the back of the rings at the front and rear faces of the rings and between the pairs of rings 22. It will be understood that each ring 22 or the ring 122 is a floating ring capabley of turning movement on the piston about the axis of the piston head and capable of radial expansion and contraction. The steam grooves 27 and passages 28 provide for almost a complete balance of the pressure at the peripheral faces lof the floating rings 'and at the backs thereof. For example, if the steam p-ressure under which the piston is operating is 200v l lbs. there will be 180 lbs. pressure, approxi.-

mately, at the periphery of rings 22, or 122,

, but 200 lbs. pressure at theback of the rings,

thereby making for net outward pressure of 20 lbs. on the rings, a pressure which maintains the piston vsufficiently steam tight to .prevent leakage past the piston but not severe enough to cut the cylinder particularly 1n View of the float-ing character of the piston ring.` The numeral 127 represents a peripheral steam groove in the .ring 122 a-nd 128 the radial steam passages, said grooves and passages corresponding with the grooves and passa es 27 and 28. l It is to noted that in the described construction the ring 20 and notI the head 10 takes the wear of the piston at the periphery and therefore in addition to the life of the piston being prolonged by the floating 'piston ring assemblage as described, the taking of the wear by the removable ring 20 indefinitely prolongs the .life of the piston head because said ring 20 alone needs to be renewed upon excessive wearand the renewal of the head or the discarding of the whole piston. is thereby obviated. l

Practical tests having demonstrated thatJ a piston constructed as described may be used for long periods without requiring repair or adjustment, a piston embodying the invention having been used on a marine engine for nearly 100,000 nautical miles without needing repair of the piston or of the cylinder in which it operated.

l would state in conclusion that while the illustrated example constitutes a practical embodiment of my invention, l do not limit myself strictly to the exact details herein illustrated, since, manifestly, the same can be considerably varied without departure from the spirit of the invention as defined in-the appended claims.

-and the walls of said spaces having interengagement, said floating rings being free to have turning movement on the piston about the axis thereof and having play radially in said spaces in the expansion and contraction of said floating rings, the interengagement between the floating rings and the walls of said spaces preventing complete displacement of the floating rings in the event of breakage thereof.

2. A piston including a head having a tapered zone, a ring having a tapered fit on said head at zone to partake of the movements of the head, said piston presenting annular spaces in the front and rea-r of said ring, the side walls of said spaces having annular grooves, and floating piston rings having members fitting in said grooves and free to play radially therein as well as to have turning movement on the piston about the axis thereof, the engagement of said members of the floating rings in said grooves preventing complete displacement of the floating rings should breakage occur. 

